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The Effects of Eisenia foetida Activity and Different Organic Residues on Some Soil Chemical Properties and Corn Growth Indicators
Mh. Rasouli-Sadaghiani, S. Ejlali , S. Ashrafi Saeidlou,
Volume 19, Issue 73 (11-2015)
Abstract

Earthworms are an important component of soil fauna because of their fundamental impact on soil physical, chemical and biological properties. To evaluate the effects of earthworms on some soil chemical properties as well as plant growth indicators, an experiment was carried out in a completely randomized design in greenhouse conditions. The first factor involved the presence or absence of earthworms (Eisenia foetida), the second factor was different organic matter including control (no organic materials), pruning waste compost of apple and grape (PWC), wheat straw (WS), Herbal extracts waste (HE), pruning waste (PW) and the third factor was the presence or absence of corn plant for evaluating rhizosphere soil. At the end of growing period, some soil chemical properties including total nitrogen, organic carbon, ammonium, nitrate and plant growth indicators were measured. The results showed that application of organic matter and earthworm inoculation had significant effects on soil chemical properties. The pruning waste compost (PWC) treatment showed the largest impact on ammonium and nitrate content (1.7 and 3.3 times compared to control treatment, respectively). In pruning waste compost (PWC) treatment, organic carbon amount in rhizospheric soil increased from 0.9 at non-rhizosphere to 1.32 %. The presence of earthworm improved plant growth parameters including shoot and root dry weight by 34% and 30%, respectively, compared to earthworm absence condition. Soil ammonium and nitrate contents at earthworm presence increased 32% and 49%, respectively. Therefore, application of organic matter with earthworm inoculation had better results in comparison with no earthworm inoculation.


Comparing Rangeland Soil-Vegetation Mineral Content Based on Elevation Classes and Phenological Stages in North-Facing Slopes, Sabalan Region, Ardabil Province
H. R. Eshghizadeh, M. Kafi, A. Nezami, A. H. Khoshgoftarmanesh, M. Karami,
Volume 19, Issue 73 (11-2015)
Abstract

This study was conducted to determine some mineral content concentrations in soils and plants of three elevation classes (1500, 2200 and 3000m) and two phenological stages of flowering and seedling in north facing slopes of Sabalan rangelands. Soil samples from the depth of 20cm and plant samples using 1×1m plots with 10 replications were collected. After sample preparation, the concentrations of minerals such as calcium, phosphorous, sodium, potassium, ion, copper, zinc and magnesium were determined using spectrophotometer and flame photometer. Data was analyzed by SAS9.1 software using a Completely Randomized Design with a Generalized Linear Model procedure. Results showed that elevation had a significant effect on Ca, Fe, Cu, Zn and Mn of soil and P, Na, K, Mg and Mn of plants in the study areas (P&le0.05). Growing stages had a significant effect on all elements of plants except Ca (P&le0.05). Moreover, results showed that in three elevation classes the high demand minerals' concentrations were higher at the starting seedling stage in comparison with the flowering stage. In contrast, the low demand minerals' concentrations in three elevation sites were higher in the flowering stage in comparison with seedling stage. Interaction effect of elevation and growing stage was also significant in relation to all elements except Ca (P&le0.05).


Comparing Rangeland Soil-Vegetation Mineral Content Based on Elevation and Phenological Stages in North-Facing Slopes, Sabalan Region, Ardabil Province
R. Valizadeh Yonjalli, F. Mirzaei Aghjehgheshlagh, A. Ghorbani,
Volume 19, Issue 73 (11-2015)
Abstract

This study was conducted to determine some mineral content concentration in soil and plant of three elevation classes (1500, 2200 and 3000m) and two phenological stages of flowering and seedling start in north-facing slopes of Sabalan rangelands. Soil samples from the depth of 20cm and plant samples using 1×1m plots with 10 replications were collected. After sample preparation, the concentrations of minerals such as calcium, phosphorous, sodium, potassium, ion, copper, zinc and magnesium were determined using spectrophotometer and flame photometer. Data was analyzed by SAS9.1 software using Completely Randomized Design with a Generalized Linear Model procedure. Results showed that elevation had a significant effect on Ca, Fe, Cu, Zn and Mn of soil and P, Na, K, Mg and Mn of plants in the study areas (P&le0.05). Growing stages had a significant effect on all elements of plants except Ca (P&le0.05). Moreover, results showed that in three elevation classes the high demand minerals’ concentration was higher at the starting seedling stage in comparison with the flowering stage. In contrast, the low demand minerals’ concentration in three elevation sites was higher in the flowering stage in comparison with seedling stage. Interaction effect of elevation and growing stage was also significant in relation to all elements except Ca (P&le0.05).


Evaluation of the Potential of Soil Microbial Activity on Cd Phytoremediation in a Contaminated Soil
M. H. Rasouli0-Sadaghiani, H. Khodaverdiloo, M. Barin, S. Kazemalilou,
Volume 22, Issue 1 (6-2018)
Abstract
The use of plants and soil microorganisms is a promising technique for the phytoremediation of heavy metal-contaminated soils. This study was carried out in order to evaluate the soil microbial potential with four Cd concentration levels (0, 10, 30 and 100 mg kg-1); the study also addressed the inoculation of arbuscular mycorrhizal fungi (AMF) species (a mixture of Glomus species including G. intraradices, G. mosseae and G. fasciculatum) as well as plant growth promoting rhizobacteria (PGPR) (a mixture of Pseudomonas species including P. putida, P. fluorescens, and P. aeruginosa) with the Centaurea cyanus plant. The soil sample was spiked uniformly with Cd nitrate salt to create different Cd concentrations. The contaminated soils were then sterilized and subsequently inoculated with AMF and PGPR. The results indicated that with increasing the soil Cd concentration, colonization percent, abundance of rhizobateria, shoot biomass, and shoot relative biomass were significantly decreased, while the  proline content and the shoot Cd concentration were significantly increased (P≤0.05). The mean of Cd extracted in AMF and PGPR treatments was 1.8 and 2.8 and the translocation factor was 1.2 and 1.5 times higher, as compared to the corresponding control treatments, respectively. It could be concluded that microbial inoculation, in addition to improving plant growth, plays an important role in the Cd phytoremediation efficiency by plant.

Determining the Effective Factors in Water Use Efficiency (WUE) of Common Bean (Phaseolus vulgaris L.), Sesame (Sesamum indicum L.) and Maize (Zea mays L.) in Response to Humic Acid Application and Deficit Irrigation
M. Jahan, B. Amiri,
Volume 22, Issue 3 (11-2018)
Abstract
Factor analysis is one of the multivariate statistical techniques that considers the interrelationships between apparently irrelevant variables and helps researchers to find the hidden reasons for the occurrence of an event. In order to evaluate the effects of different irrigation levels and humic acid foliar application and identify the factors affecting water use efficiencies of sesame (Sesamum indicum L.), maize (Zea mays L.) and common bean (Phaseolus vulgaris L.), a split plots experiment based on RCBD design with three replications was conducted during the 2014-15 growing season, at the Research Farm of Ferdowsi University of Mashhad, Iran. Irrigation levels (50 and 100% of water requirement) and foliar application and non-application of humic acid were assigned to main and sub plots, respectively. The results showed that in sesame, the highest seed yield and biological yield were obtained from 100% of water requirement and humic acid spraying treatment. In maize, humic acid spraying under condition of supplying 50% of water requirement increased seed weight per plant, plant height, and leaf area index and soil pH In bean, the highest seed weight per plant, plant height, leaf area index, crop growth rate and soil phosphorous content were observed in the treatment of 100% of water requirement and humic acid spraying. Factor analysis results also showed that in sesame, the variables of seed yield, biological yield, seed weight per plant, plant height, leaf area index, crop growth rate, soil phosphorous and water use efficiency were assigned to the first factor and the variables of soil nitrogen, soil pH and EC were assigned to the second one. In maize, seed yield was assigned in the same group with the variables of biological yield, leaf area index, crop growth rate, soil phosphorous, EC and pH and water use efficiency; in bean, this was with the variables of seed yield and water use efficiency. In general, the research results revealed that identifying the effective variables in each factor and those logical nominations according to Eco physiological knowledge can lead to the direct management of effective variables with regard to associated factor, thereby leading to water efficiency improvement.

Evaluation of Different Irrigation Methods of Hedysarum criniferum Boiss. under Field Conditions
O. Asadi Asadabad, S. H. Matinkhah, Z. Jafari, H. Karim Mojeni,
Volume 25, Issue 1 (5-2021)
Abstract
In order to investigate the effect of the type drip of irrigation methods, subsurface irrigation and furrow irrigation on the domestication of Hedysarum criniferum Boiss., an experiment with a  randomized complete block design with three replications was implemented  at Isfahan University of Technology for two years (2016 to 2018) . For this purpose, clay pipes were made and the plant was cultivated on the sides of clay pipes and types. Also, furrow irrigation treatment was applied as the control. During the experiment, all treatments received the same water and finally, some growth parameters were measured. The results of the study showed improvement in height (0.43 and 0.34), canopy cover (0.66 and 0.52), stem number (0.44 and 0.85), chlorophyll index (0.45 and 0.45), seed emergence (0.75 and 0.30), plant survival (0.78 and 0.55), yield (0.23 and 0.35), and water use efficiency (0.25 and 0.25) under type drip irrigation treatment, as compared to subsurface and furrow irrigation, respectively (P<0.05). In general, the type drip treatment is recommended in the early years of planting; however, since the maximum production potential of this plant is in the third year onwards, it is necessary to examine the results in the following years to recommend the proper irrigation method, especially the use of subsurface irrigation. 

Regional Frequency Analysis of Drought Severity of SEI-SRI and SEI-SSI Indices in Common Duration Using Multivariate L-Moments and Copula Functions (Case Study: Karkheh River Basin)
S. Parvizi, S. Eslamian, M. Gheysari, A.r. Gohari, S. Soltani Kopai, P. Mohit Esfahani,
Volume 26, Issue 3 (12-2022)
Abstract
Investigation of homogeneity regions using univariate characteristics is an important step in the regional frequency analysis method. However, some hydrological phenomena have multivariate characteristics that cannot be studied by univariate methods. Droughts are one of these phenomena their definition as univariate will not be effective for risk assessment, decision-making, and management. Therefore, in this study, the regional frequency analysis of drought was studied in multivariate methods using SEI (Standardized Evapotranspiration Index), SSI (Standardized Soil Moisture Index), and SRI (Standardized Runoff Index) indices in the Karkheh River basin from 1996 to 2019. The indices calculated probabilistic distribution between the variables of evapotranspiration, runoff, and soil moisture using multivariate L-moments method and Copula functions and considered meteorological, agricultural, and hydrological droughts simultaneously. The results of multivariate regional frequency analysis considering the Copula Gumbel as the regional Copula showed that the basin is homogeneous in terms of severity of SEI-SSI combined drought indices and is heterogeneous in terms of severity of SEI-SSI combined drought indices. However, after clustering the basin into four homogeneous areas in terms of characteristics of SPI (Standardized Precipitation Index), the basin is homogeneous in all areas in terms of univariate SEI, SSI, and SRI indices and is heterogeneous in the third and fourth clusters of SRI and SSI drought indices. Pearson Type (III), Pareto, normal, and general logistics distribution functions were found suitable to investigate the characteristics of SEI, SSI, and SRI drought indices in this case. Finally, large estimates of the types of combined droughts and their probability of occurrence showed that the northern and southern parts of the Karkheh River basin will experience short and consecutive droughts in the next years. Droughts in areas without meteorological data can be predicted in terms of joint probability using the multivariate regional frequency analysis method proposed in this study.

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